From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 106C51448F3; Thu, 11 Apr 2024 10:04:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712829888; cv=none; b=EBbNAtKnJ7982XqO4H97CfQDTe4enlfus/G6I0sxtkzf7rRPhNjbuVDmKfiPvcQx9qWU+MQkzJlUpyThZtfl3ZbFUww2U+WtagRlKLLzEBiA7qx/aY0514DhxdueWfaw4npYwdnFUiTkpD/hKgui4Kbay7W0owaOGo16Q9Of09k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712829888; c=relaxed/simple; bh=WQPMEGC32YQOvdqseAEt5zuAjZztPfKgOfwJ95r8JKw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Xyq3w0A39nssQeMn7PTD5c0ezNKoLXHKLJqUF9Pi9hcxkWs/1Moa9QqBzW2aOVtW5zQcn9yW5OgyHfZZMy+YqEeLPDSsS1gK7jVO4yvG+E215HbNrrmIyikh/jDR0TFw5UmZ9JODzxqT2uNZ+5lLqPX35l603Y7YnU24xgq+vLQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=IjpjGel7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="IjpjGel7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B1C8C433C7; Thu, 11 Apr 2024 10:04:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712829887; bh=WQPMEGC32YQOvdqseAEt5zuAjZztPfKgOfwJ95r8JKw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IjpjGel7pNMFxDbNSwhRqxVFGzIDKagaLyjbxTctNXHRI5PIIxxNjtifX1MGXSYSr JDHFWF34jy+aXy0LYaJNaBBbDs6Mwgvi43mm6x5K5gCbZ6iUZ/WGxAe16Y+SVXpVY3 aOgjdteoYoBbiVSa2yzF77mgtyKefRbv/ulHdCLo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ziyang Xuan , Pablo Neira Ayuso Subject: [PATCH 4.19 122/175] netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get() Date: Thu, 11 Apr 2024 11:55:45 +0200 Message-ID: <20240411095423.240594412@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240411095419.532012976@linuxfoundation.org> References: <20240411095419.532012976@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ziyang Xuan commit 24225011d81b471acc0e1e315b7d9905459a6304 upstream. nft_unregister_flowtable_type() within nf_flow_inet_module_exit() can concurrent with __nft_flowtable_type_get() within nf_tables_newflowtable(). And thhere is not any protection when iterate over nf_tables_flowtables list in __nft_flowtable_type_get(). Therefore, there is pertential data-race of nf_tables_flowtables list entry. Use list_for_each_entry_rcu() to iterate over nf_tables_flowtables list in __nft_flowtable_type_get(), and use rcu_read_lock() in the caller nft_flowtable_type_get() to protect the entire type query process. Fixes: 3b49e2e94e6e ("netfilter: nf_tables: add flow table netlink frontend") Signed-off-by: Ziyang Xuan Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nf_tables_api.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -5721,11 +5721,12 @@ static int nf_tables_flowtable_parse_hoo return err; } +/* call under rcu_read_lock */ static const struct nf_flowtable_type *__nft_flowtable_type_get(u8 family) { const struct nf_flowtable_type *type; - list_for_each_entry(type, &nf_tables_flowtables, list) { + list_for_each_entry_rcu(type, &nf_tables_flowtables, list) { if (family == type->family) return type; } @@ -5737,9 +5738,13 @@ nft_flowtable_type_get(struct net *net, { const struct nf_flowtable_type *type; + rcu_read_lock(); type = __nft_flowtable_type_get(family); - if (type != NULL && try_module_get(type->owner)) + if (type != NULL && try_module_get(type->owner)) { + rcu_read_unlock(); return type; + } + rcu_read_unlock(); lockdep_nfnl_nft_mutex_not_held(); #ifdef CONFIG_MODULES